Assertion (A): Herbivores are called first order consumers.
Reason (R): Tiger is a top carnivore.

Options

A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are true but Reason is NOT the correct explanation of Assertion.
C. Assertion is true but Reason is false.
D. Assertion is false and Reason is true.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Herbivores are called first order consumers."
- In an ecosystem, herbivores (like deer and cattle) feed directly on producers (plants). Since they are the first to consume the energy from producers, they are classified as first order consumers.

2. **Understanding the Reason**:
- The reason states that "Tiger is a top carnivore."
- A top carnivore is an organism that is at the highest trophic level in an ecosystem and is not preyed upon by other animals. Tigers, being apex predators, fit this description as they have no natural predators.

3. **Evaluating the Truth of Both Statements**:
- Both statements are true:
- Herbivores are indeed first order consumers as they consume producers.
- Tigers are classified as top carnivores since they are at the top of the food chain.

4. **Determining the Relationship Between Assertion and Reason**:
- While both statements are true, the reason (Tiger is a top carnivore) does not explain the assertion (Herbivores are first order consumers). The classification of herbivores as first order consumers is based on their role in the food chain, while the classification of tigers as top carnivores is based on their position in the food chain. Thus, the reason does not provide a correct explanation for the assertion.

5. **Conclusion**:
- The correct answer is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
Both A and R are true, but R is not the correct explanation of A.

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